<?php
  /**
  * Copyright 2011 Facebook, Inc.
  *
  * Licensed under the Apache License, Version 2.0 (the "License"); you may
  * not use this file except in compliance with the License. You may obtain
  * a copy of the License at
  *
  *     http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
  * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
  * License for the specific language governing permissions and limitations
  * under the License.
  */

  require 'includes/facebook.php';

  define('FACEBOOK_APP_ID',"160596754040030");
  define('FACEBOOK_SECRET',"20ea9c13cac64e709f346cac489669f9");

  $user = null;

  // Create our Application instance (replace this with your appId and secret).
  $facebook = new Facebook(array(
  'appId' => FACEBOOK_APP_ID,
  'secret' => FACEBOOK_SECRET,
  'cookie' => true
  ));

  // Get User ID
  $user = $facebook->getUser();

  // We may or may not have this data based on whether the user is logged in.
  //
  // If we have a $user id here, it means we know the user is logged into
  // Facebook, but we don't know if the access token is valid. An access
  // token is invalid if the user logged out of Facebook.

  if ($user) {
    try {
      // Proceed knowing you have a logged in user who's authenticated.
      $user_profile = $facebook->api('/me');
    } catch (FacebookApiException $e) {
      error_log($e);
      $user = null;
    }
  }   

  // Login or logout url will be needed depending on current user state.
  if ($user) {
    $logoutUrl = $facebook->getLogoutUrl();

  } else {
    $params = array('scope' => 'email, publish_actions, publish_stream, read_stream, offline_access');
    $loginUrl = $facebook->getLoginUrl($params);
    echo("<script> top.location.href='" . $loginUrl . "'</script>");
    exit();
  }

 var_dump($user_profile);                       
?>